So a bit of looking around, and a quick toodle on Windows has confirmed using AT commands I can connect to a serial port and send an SMS.

A bit of google-foo has told me this should also be possible on OpenWRT - on which gargoyle is based.

But what I'd like is to be able to call a page on my router with some phone numbers and a message, so that I can have SMS sending from various machines at home (ie my alarm, and or a windows program).

Anyone know of a easyish way of doing this?  I could hook it to my windows server (and pass it though to linux - or do it in windows), but I liked the idea of doing it with my router, which generally should always be up.